Sets MACOSX_DEPLOYMENT_TARGET variable

[p0nce]

to avoid trivial incompatibility with OSX version earlier than the one used to build DUB

It avoids the Illegal instruction error.

I've tested on OSX 10.6.8 and the next error is:

dyld: Library not loaded /usr/lib/libcurl.4.dylib
Referenced from: /path/to/dub
Reason: Incompatible library version: dub requires version 7.0.0 or later, but libcurl.4.dylib provides version 6.0.0
Trace/BPT trap

[s-ludwig]

I think that library incompatibility might be fixed with DMD 2.069, because libcurl is loaded dynamically there. But since this is a Phobos dependency, there is nothing that can be done from DUB's side.

BTW, any reason why an explicit export is needed?

[p0nce]

BTW, any reason why an explicit export is needed?

I've checked and indeed it isn't needed.

But since this is a Phobos dependency, there is nothing that can be done from DUB's side.

Let's just wait DMD 2.069 then, nothing urgent. One can build on another machine.

[s-ludwig]

Okay

[jacob-carlborg]

Next version of DMD and the current version of LDC have a minimum requirement of OS X 10.7.

[p0nce]

I target OS X 10.7+ for this reason, and don't need a DUB running on OS X 10.6 anymore. Do you want another PR?

[s-ludwig]

Will/does setting it to 10.6 cause build issues with those compilers?

[p0nce]

If phobos is built with 10.7 as minimum OS version then it could create problems if we don't do the same. Though I don't really know what could happen.

[jacob-carlborg]

Will/does setting it to 10.6 cause build issues with those compilers?

@s-ludwig yes:

$ cat main.d
int a = 3; // TLS
void main() {}

$ ./dmd main.d -L-macosx_version_min -L10.6 -L-lcrt1.10.6.o
ld: targeted OS version does not support use of thread local variables in _D4main1ai for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
--- errorlevel 1

Targeting 10.7 works perfectly fine: ./dmd main.d -L-macosx_version_min -L10.7 -L-lcrt1.o

[s-ludwig]

Okay, incremented to 10.7 now.